2011super duty blower motor replacement

Remove the blower motor relay. Disconnect blower motor. At the blower motor connector, check for continuity from the BN/OR wire to the battery negative post (or a verified frame ground). Likely it will show zero ohms or low impedance (a few ohms)

If true, likely there's is a short somewhere along the length of the cable BN/OR wire to chassis.

Comment for further assistance.

It is most likely the blower motor resistor assembly. You may be able to go online/Youtube for a DIY on replacing blower motor resistor assembly. Probably the same as an F250 SuperDuty pickup truck.

RR/HVAC fuse 30amp located in the under hood fuse box. You can check it but highly doubt it's the problem . More then like it's the blower motor control module that's bad .
Circuit/System Description
The auxiliary blower motor is a variable speed fan. The HVAC control module controls the fan speed by sending a pulse width modulated signal to the auxiliary blower motor control module. The auxiliary blower motor control module varies the duty cycle across the auxiliary blower motor in relation to the pulse width modulated signal. The auxiliary blower motor speed can be adjusted from 10 percent to 90 percent duty cycle (PWM), 90 percent is high speed fan.
Watch this video for testing purpose's only , this is a front blower motor control module . Same way your back one works . GM is GM Chevy , Buick ,GMC , Cadillac .

Blower motor in engine compartment passenger firewall area, you may have to remove the cruise control servo to get motor out, very easy and straightforward job, be careful transferring the blower motor wheel over to new motor, remove lockclip first on motor shaft.

This is one of two failures either the front power transistor or the blower motor. If the power transistor is failed, then the blower motor has to be replaced also. This is a very common failure.

see the steel wire behind the speed control blower switch. it might just be loose.

Blower Motor Removal & Installation Delphi
Blower Motor Replacement (Delphi)


To Remove:

1. Remove the instrument panel sound insulator panel (if equipped).
2. Disconnect the electrical connector from the blower motor.
3. Remove the blower motor insulating cover screws.
4. Remove the blower motor insulating cover.
5. Pull the retaining tab down and rotate blower motor counterclockwise to remove.

To Install:

1. Position the blower motor and turn assembly clockwise until tab locks in place.
2. Install the blower motor insulating cover.
3. Connect the electrical connector to the blower motor.
4. Install the instrument panel sound insulator panel (if equipped).

Visteon

Blower Motor Replacement (Visteon)


To Remove:

1. Remove the instrument panel sound insulator panel (if equipped).
2. Disconnect the electrical connector from the blower motor.
3. Remove the blower motor screws.
4. Remove the blower motor from the HVAC module.

To Install:

1. Position the blower motor and install mounting screws.
2. Connect the electrical connector to the blower motor.
3. Install the instrument panel sound insulator panel (if equipped).

it's either the blower motor switch or blower motor resister. Resistor ?Heater Blower Motor Switch Removal Remove the battery (10655) ; refer to Section 414-01 . Remove the battery tray. Remove the screws. Remove the battery tray. Disconnect the heater blower motor switch resistor connector. Remove the heater blower motor switch resistor (18591). Remove the two screws. Remove the heater blower motor switch resistor. ----------------------------------- Switches Removal Disconnect the battery ground cable. Remove the center trim panel; refer to Section 501-12 . Remove the control assembly. Remove the screws. Remove the control assembly. Remove the A/C-heater function selector switch knob. Disconnect the vacuum harness connector. Disconnect the A/C-heater function selector switch connector. Remove the A/C-heater function selector switch. Remove the screw. Remove the A/C-heater function selector switch. Remove the temperature control switch knob. Disconnect the temperature control switch connector. Remove the temperature control switch. Remove the screw. Remove the temperature control switch. Remove the heater blower motor switch knob. Disconnect the heater blower motor switch connector. Remove the heater blower motor switch (18578). Remove the screw. Remove the heater blower motor switch. ----------------------------

If it's the blower motor,the vacuum pump has to be moved out of the way(10 mm bolts) . There are three or four 8mm bolts holding the motor in place. make sure you have power and ground to blower motor before replacing.

I took my truck in and they removed the blower and cleaned it now works great did not need to replace it.